<template>
  <div>数字:{{ num }}</div>
  <button @click="add">+1</button>
  <button @click="dec">-1</button>
</template>
<script setup>
import { ref } from 'vue';
    let num = ref(1);
    function add(){
       num.value++;
    }
    function dec(){
        num.value--;
};
</script>

<style>
</style>